1. Field of the Invention
The present invention pertains to post drivers. More particularly, the present invention pertains to a multipart guide collet that can easily be detached from a post in the event that the end of the post deforms.
2. General Background
Post drivers are used to drive posts axially into the earth or other materials. Such posts may be rods, bars, tubes, etc. For example, post drivers are often used to drive rebars into the ground. A typical post driver comprises a hammer that reciprocates and intermittently strikes an anvil. The anvil engages an axial end of the post being driven. The impact loads are thereby transferred from the anvil to the post so as to drive the post. In some cases the anvil is movable relative to the rest of the post driver such that the remainder of the post driver does not experience the impact loads. To eliminate torsion loads on the anvil, the post preferably should be axially aligned with the center of mass of the anvil. Of course, not all posts have the same diameter and it's therefore desirable to configure a post driver to handle posts of different diameter. Thus, a post driver is often provided with various bolt-on collets/adapters adapted for specific post diameters for radially guiding the post relative to the anvil. On occasion, the end of a post may become mushroomed, which often makes the post difficult to remove from such collets.